BP and the oligarchs will now enter arbitration proceedings at a United Nations court in Sweden.

Speaking before the injunction was granted, Mr Dudley acknowledged that any settlement to Alfa Access Renova may be financial.

However, Mr O'Brien said it was unlikely anything would be settled before the arbitration process, which the two sides are hoping to complete before February 25.

"Anything is possible but in reality I do not see a resolution before the start of the arbitration process," Mr O'Brien said,

Rosneft, the world's largest oil producer, chose BP as its partner to drill in the deep Arctic waters of the Kara Sea under the share swap deal. Its chairman is Igor Sechin, the powerful deputy of Russian prime minister Vladimir Putin.

The deal with BP has also drawn criticism from Yukos, the company formerly run by jailed oil man Mikhail Khodorkovsky. Rosneft swept up most of the fields that had belonged to Yukos after Mr Khodorkovsky had been convicted of fraud and sentenced to nine years in jail in 2003.

In America, several politicians have also raised concerns, apparently on grounds of "national and economic security", at a time when BP's image has already been harmed by the Gulf of Mexico oil spill last year.